Hello List
Please help us settle a disagreement about procedure.
The goal is to a print standard for our packaging at the highest possible quality on an offset sheet press and maintain consistency in EU and US.
Do you agree or disagree with the following procedure?
Print a test sheet (including an IT8 chart) on a Heidleberg DI press and run it to a visual approval by the Quality Manager. Then give that DI press sheet to the offset vendors and tell them to match the quality. The idea is to push them to achieve the highest possible quality.
You need a little more than the press sheet to the vendors. They need to
know how you got there - what were the separation settings, GCR, dot gain,
max density, etc. Also did you use standard inks, paper, density settings.
It would be most straight forward to pick a print standard like SWOP or
Gracol (sheetfed larger gamut) with specs readily available and used by
many. And you know that they are reasonably/ consistently obtainable. In
other words you need more than a visual approval, you need numbers and specs
so it is truly repeatable, by you as well.
Hello List
Please help us settle a disagreement about procedure.
The goal is to a print standard for our packaging at the highest possible
quality on an offset sheet press and maintain consistency in EU and US.
Do you agree or disagree with the following procedure?
Print a test sheet (including an IT8 chart) on a Heidleberg DI press and run
it to a visual approval by the Quality Manager. Then give that DI press sheet
to the offset vendors and tell them to match the quality. The idea is to push
them to achieve the highest possible quality.
Agree or Disagree?
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Why is the Quality Manager the approver? If all you’re going by is visual approval, the customer would have to approve every job. Remeber, color is a relative sensation. (relative to the observer)
The right way to get an approval is to determine your target standard (TR001 is the only likely choice at this point, unless you’re separating in house, and separating to some other standard) then print to those solid ink density and dot gain specs. When your sheet meets those specifications, your sheet is measureable and repeatable.
So you’re giving your vendors a proof. The fact that it’s printed on your DI press means little more than you’ve made a very expenisve proof! Your proofing system should be replicating your press output, that’s what a proof is for!
If the idea is to push for quality, then give them specifications to print to. Specify the important things like paper color, ink color (in Lab* at density), Solid ink densities, dot gains, etc… Giving them a sheet from a press (or even a proof) means nothing if they don’t know how that sheet (prrof) was created.
Here’s the beauty of this system. Make one file and send it to any printer in the world that’s capable of and advertisies they print to SWOP (TR001). When you get the product back, it will match! If it doesn’t, you can tell them exactly why. (Because you know what to expect and can measure it)
There’s nothing wrong with supplying a proof to your vendors, just make sure it’s printed to a specification and that specification can be met and repeated. (for instance, don’t run Magenta at 1.8 because you want more “punch” in the red… that’s out of spec and some inks may not get to 1.8 without a TON of gain)
On a DI first there is a laser linearization process that revolves around a built in 50% screen. This should be stored on the DI’s internal hardrive if it is the original drive the DI was set up with. Then there is the Ink Linearization process for the DI . Then you are ready to do the match proof if thats the way you want to do it.
What we do is finger print our large offset press’s since this is the backbone of our orginization. Then we move the DI to print in the Offset color space. Takes a bit but the DI can do very well.
Since it is a dry process and uses a different ink set its not as clear a procedure as one would think
Do you find that your “large presses” differ greatly from the specification you’re printing to? What are you doing to control your output on those large presses? Do your DI machines have consumables and settings capable of reaching that specification? I guess the first question is “are you trying to reach a specification, like SWOP, in the first place?”
It’s crystal clear when you’ve chosen a standard to print to. Big press or small, ink set A or B, wet or dry offset, AM or FM screening, the process upstream of the press should be tooled to meeting a specification of some sort. Be it TR001 (SWAP) or some other industry specification, the key is to make the output of each process meet that specification.
If your specification is an arbitrary one, let’s say that of the highest producing machine in the plant, the that machine’s output needs to be well controlled, well understood and known to be repeatable. Your customers would also need to know that machine’s output so that they may separate to match. (Assuming it does not meet an industry standard that is commonly separated to.) Change the rollers in that press and your entire specification has changed!
I get a lot of flack for pushing the industry specs, so I feel like I should sum this up…
Why push the industry specs?
If you’re not separating in-house, you have to push the industry specs because in most cases, the customer is largely ignorant of the settings they’re using to separate. Don’t believe it? Ask a customer how their files get from RGB to CMYK.
In every Adobe, Macromedia or Microsoft application, the default for (Insert color space here, usualy RGB) to CMYK matches the specification for SWOP. So when the customer, ignorant of their choices or not, separate their images to CMYK, they’re using (and therefore expecting) SWOP output.
If you’re printing at anything other than SWOP, there’s a higher likelihood that your output is not going to match their expectations. (Unless they’re providing a proof… in which case… who knows!)
I’ll get off my soapbox now! Thanks for listening!
Naw get back on your soap box. The one thing we need is standards. I have been in the printing industry for twenty years. The first fifteen years we flew by the seat of our pants running off my eyeball. Its only been the last five years we have had the tools in our shop to measure and adopt standards. The one we have been using the last few years is the Gracol standard. The Gracol 7 spec is really exciting. Imagine being able to take your job to any shop, any press and get basically the same job. All by balancing your neutral grays. And all it will take is all the printers going to this standard. (lots of soapbox time ahead)
The DI press being so different from a wet offset press can produce the same look using grey balance.
Now if you have profiled to a Gracol calibrated press and produced a proof from that profile and your proofing device is profiled correctly you should be able to take that proof anywhere they are using Gracol. And they will match that proof. With Gracol 7 they are talking about a universal press profile that will work any where they are using Gracol 7. Wouldn’t that be great but I am taking that with a grain of salt for now.
But back to the original question. A standard for highest possible quality in a offset press. I like Gracol, don’t think you need a DI Press proof to give your vendors. Look for Gracol Printers, use a Gracol Press Profile, give them the proofs created from this and insist on consistency
